Chemical deactivation of catalyst at both faces of a cellulosic fabric impregnated with a resin-catalyst system to improve abrasion resistance of fabric after curing



United States Patent 3,402,988 CHEMICAL DEACTIVATION OF CATALYST AT BOTHFACES OF A CELLULOSIC FABRIC IM- PREGNATED WITH A RESIN-CATALYST SYS-TEM TO IMPROVE ABRASION RESISTANCE OF FABRIC AFTER CURING Wilson A.Reeves and Albert S. Cooper, Jr., Metairie, La., assignors to the UnitedStates of America as represented by the Secretary of Agriculture NoDrawing. Filed Apr. 2, 1965, Ser. No. 445,281

3 Claims. (Cl. 8-116) ABSTRACT OF THE DISCLOSURE This invention relatesto a method for producing wrinkle and abrasion-resistant cellulosictextiles, More particularly, this invention relates to a method forproducing wrinkle and abrasion-resistant cellulosic textiles that areessentially free of cross-linked cellulose molecules in selectedportions of the textile but contain crosslinked cellulose moleculesthroughout the interior of the textile structure.

A non-exclusive, irrevocable, royalty-free license in the inventionherein described, throughout the world for all purposes of the UnitedStates Government, with the power to grant sublicenses for suchpurposes, is hereby granted to the Government of the United States ofAmerica.

This invention relates to a method for producing wrinkleandabrasion-resistant cellulosic fabrics and to the product so produced.More specifically, it deals with a method for producing wrinkleandabrasion-resistant cellulosic textile fabrics that are essentially freeof crosslinked cellulose molecules in selected portions of the fabricbut contain crosslinked cellulose molecules throughout the interior ofthe fabric structure. The fabrics resulting from the process of thisinvention are characterized by excellent abrasion resistance, creaseretention, unimpaired surface dyeing properties, smooth drying, and ahigh degree of wrinkle resistance.

The term crosslinked cellulose as used herein refers to cellulosemolecules contained in cellulosic fibers that have been reacted with acellulose reactive reagent (usually a polyfunctional reagent) to the endthat adjacent cellulose molecules are joined together. Crosslinkedcellulose is characterized by relative insolubility in conventionalcellulose solvents, such as cuprammonium hydroxide.

The term wash-wear finish as used herein refers to a chemical treatmentapplied to cellulosic textiles for the purpose of crosslinkingcellulosic molecules and imparting thereby wrinkle-resistance andsmooth-drying properties to the textiles.

The present invention is related to copending application of Albert S.Cooper, Jr., and Wilson A. Reeves entitled Abrasion Resistant Wash-WearCellulosic Fabrics, having Ser. No. 445,282 and filed concurrentlyherewith.

Heretofore cellulosic textiles treated with a wash-wear finish exhibitedgreatly reduced abrasion resistance and impaired receptability to dyes.The wash-wear finish in the conventional processes for producing wrinkleresistant fabrics penetrates the entire fabric structure causingcrosslinking of the cellulose molecules throughout the fibrousstructure. When these conventionally processed wash-wear fabrics aremade into garments, such as shirts, dresses, and trousers, the fabricssoon show excessive abrasion at the pockets, collars, knees, creases,and at other exposed areas. The reduced abrasion resistance as comparedto noncrosslinked cotton fabrics is due largely to crosslinked cellulosein the fibers located at the fabric surface. More 3,402,988 PatentedSept. 24, 19 68 ice recently, wash-wear fabrics have been made intogarments, especially men's trousers, through the use of delaycuredprocesses, and these garments exhibit sharp durable creases as well aswrinkle resistance and smooth drying properties. Trousers of this typefabricated predominately from cellulosic fiber exhibit very poorresistance to abrasion. Small holes, in some instances, are abraded inthe cuffs and creases by merely laundering and tumble drying the garmenta few times. Low abrasion resistance has caused many textile finishersto use fabrics containing a blend of noncellulosic and cellulosic fibersin an effort to overcome the loss in abrasion resistance. The use ofthese blends has caused a substantial increase in the cost of wash-wearfabrics and garments.

We have now discovered that wrinkle-resistant, smoothdrying cottonfabrics with durable creases, good shapeholding properties, excellentabrasion resistance, and unimpaired dyeing properties can be produced ina remarkably simple and efficient manner. The process of our discoveryconsists essentially of impregnating cellulosic fabric, using any ofseveral conventional techniques, such as fogging, and immersion methods,with a wash-wear formulation containing a crosslinking agent, a catalystfor activating the crosslinking agent, and auxiliary finishing agents;subsequently, applying a catalyst deactivator to the top, the bottom, orboth, of the fabric, care being exercised to prevent the deactivatorfrom penetrating the entire thickness of the fabric. The catalyst isthereby neutralized or deactivated only in those regions of the fabricpenetrated by the deactivator. The fabric is then dried, and finallyheated for at least 1.5 minutes at an elevated temperature.

The process of our invention is compatible with both conventional fabricfinishing equipment and conventional fabric finishing processes, and wehave accordingly operated the process on commercial-size equipment.

The improved abrasion resistance and other properties, whichcharacterize the fabrics finished according to the process of ourinvention, as compared with the corresponding properties of wash-wearfabrics produced by the prior art processes, is due to the absence ofcrosslinked cellulose at or near the surface of the fabric.

Crosslinking agents suitable for use in this invention include reagentsthat contain two or more functional groups that are capable of reactingwith cellulose when activated by a catalyst. In general, thecrosslinking agents are those used in conventional processing methods bythe textile finishing industry for the production of wash-wearcellulosic fabrics and are also well known as crease proofing agents forcellulose. Typical examples are dimethylol urea, dimethylol ethyleneurea, N,N-dimethylol-4,5-dihydroxy ethylene urea, dimethylol hydroxyethyl carbamate, bis-methoxymethyl-ethyl carbamate,tris-(l-aziridinyl)phosphine oxide, vinyl cyclohexene diepoxide,formaldehyde, methylol and methylolated methylol triazine derivatives,acetals, and the like.

The nature of the crosslinking agent is in no way a limiting feature ofthis invention except that its reaction with cellulose must be activatedby a suitable catalyst.

The amount of crosslinking agent employed will depend to some extentupon the commercial equipment employed and the type of fabric used.Aqueous solutions of the crosslinking agent ranging from about 4 to 20weight percent (on the weight of the solution) (OWS) when the wet pickupis about 60 to 70 weight percent on the weight of the cellulosicmaterial (OWF) cause good results to be obtained. The dry weight of thecrosslinking agent will range from about 2 to 15 weight percent (OWF).

Catalysts suitable for use in this invention are those commonly usedwith crosslinking agents of the type listed above. Typical examples areamine hydrochlorides, magnesium chloride, zinc nitrate, and zincfluoroborate. The nature of the catalyst is likewise not a limitingfeature of this invention.

The amount of catalyst employed will depend upon the amount ofcrosslinking agent. However, amounts ranging from about 1 to weightpercent (OWS) is a gOOd practice. The particular catalyst to be usedwith a particular crosslinking agent is known to those skilled in theart.

Auxiliary agents suitable for use in this invention are softeners,wetting agents, optical whiteners, and other commonly used finishmodifiers. These auxiliary agents are not limiting features of thisinvention.

The prescribed use of a catalyst deactivator is the critical feature ofthis invention. The term catalyst deactivator as used herein refers to aLewis base capable of reacting with the catalyst which induces thecrosslinking reaction to neutralize or otherwise make it ineffective forpromoting the crosslinking of cellulose. Typical deactivators includesodium and other alkali hydroxides, NaHCO Na CO Ca(OH) NH amine salts,aliphatic and aromatic amines, salts of carboxylic acids, such as sodiumcarboxymethyl cellulose, and zirconyl ammonium carbonate. The controlledpenetration of the deactivator into the fabric is of utmost importance.The deactivator may be applied to the fabric surface by coatingprocedures, by spraying, fogging, or by exposure of the fabric to basicvapors. Regardless of the method of applying the deactivator, a criticalfeature of this invention is that the deactivator contact the surfaceand penetrate less than about one-half the thickness of the fabricwhether applied to one or both sides of the fabric.

When the deactivator is applied to the fabric by use of coating devices,the viscosity of the deactivator or its carrier should be great enoughto limit its penetration into the fabric less than about one-half thethickness of the fabric. Penetration will be discussed below. The typeof coating device is not critical as long as it is capable of applyingan adequate amount of the deactivator. Many compounds and polymers aresuitable for regulating the viscosity. Typical substances includestarch, derivatized starch, hydroxyethyl cellulose, methyl cellulose,carboxymethyl cellulose, silica, gelatin, polyoxyethylene, and agaragar.The preferred viscosity regulating compounds are those that impartadequate increase in viscosity with less than about of the substance insuspension or solution. The viscosity regulating agent may containgroups such as the hydroxy that are capable of reacting with thecrosslinking agent but this is not a requirement. The viscosityregulating agents which do contain such groups become chemically boundto the fabric and increase the stiffness of the treated fabric which isdesirable for many end uses of the fabric. The catalyst-deactivatorliquid may also contain a water insoluble film-forming polymer, such asnylon, polyurethane, silicones, fluorocarbons, and polyethylene whichmay be deposited on the surface of the fabric and become firmly fixed tothe fibers through mechanical or secondary valence forces when thefabric is subsequently dried and heated above 100 C. The primary purposeof these polymers is to provide a highly abrasive-resistant polymer onthe fibers at the surface of the fabric. The catalyst deactivator can beapplied to the wet fabric immediately after the wash-wear formulation isapplied; or the fabric can be dried first. When the latter method isused, the fabric is again dried after the catalyst-deactivator isapplied.

Penetration of the deactivator into a fabric structure is controlled by(l) regulation of viscosity of the fluid system, (2) controlling thetime lapse between application of the deactivator and immobilization ofit by drying the wet fabric, and (3) regulating the concentration of thedeactivator in the fluid system. Fabric weight and surface structuredetermine the limitations of these variables. The sooner the fabric isdried after the deactivator is applied the more limited will be theextent to which the deactivator penetrates the fabric, assumingviscosity and concentration are held constant. Preferably, the fabric isdried within about five minutes after the deactivator is applied to thefabric.

After the deactivator is applied, the fabric can be dried and cured topromote the crosslinking reaction in a single operation or the fabriccan be dried, made into garments, and finally cured in garment form.When the fabric is to be dried and cured in a single operation, thetemperature should be above about 285 F. and the heating should beapplied for at least about 1.5 minutes. When the fabric is to be dried,later made into garments and subsequently cured, the fabric should bedried to a moisture content of less than about 15% by heating at atemperature of less than about 260 F. The dried, but uncured, fabric canbe made into a garment such as trousers or blouses and creases andpleats can be set in the fabric at desired locations by pressing with ahot iron. The final cure or heat treatment cure which promotes reactionof the crosslinking agent with the cellulose molecules can. then be donewith a hot iron, hot head press, but is done preferably in a forceddraft hot air oven. The cure temperature in any case should be aboveabout 285 F., and the time ranges from about 1.5-15 minutes, dependingupon the weight of the fabric to be cured and the amount of crosslinkingagent contained in the fabric.

Fabrics suitable for use in this invention are composed largely ofcellulosic fibers. The fibers may be of natural or synthetic origin.They may be grey, scoured, mercerized, bleached, or dyed goods. Cottonand rayon fibers are particularly suitable. When the fabric is composedof blends of noncellulosic and cellulosic fibers, the cellulosic fibersshould make up at least 50% of the fabric weight. The fabrics may be ofthe conventional nonstretch type or they may have a high degree ofstretch and recovery. The stretch may be provided by crimped yarn suchas that produced by crimped nylon yarn or the stretch fabric may beslack mercerized cotton or rayon fabric. It is essential that thecellulosic fibers in such stretch fabrics be free from previousWash-wear finishes. The use of stretch fabrics is particularly desirablewhen a very high degree of abrasion resistance is desired.

It is within the scope of our invention to apply the crosslinking agentto a dyed, or undyed, fabric and subsequently deactivate the catalyst inselected portions of the cellulosic material. This may be on one side,on both sides, or by printing designs on one or both sides. When thetreated fabric is dried and heat-treated, the portions that have beentreated with the catalyst deactivator remain unmodified and may be dyedwith cotton dyes to give a solid shade or a design on the dyed, orundyed, background. Typical cotton dyes suitable for dyeing are thecommercially available vat dyes, such as Vat Yellow 1 (Color Index No.70600), Vat Orange 1 (Color Index No. 59105), Vat Orange 4 (Color IndexNo. 59710), Va-t Red 1 (Color Index No. 73360), Vat Violet 1 (ColorIndex No. 60010), Vat Brown 1 (Color Index No. 70800), Vat Green 1(Color Index No. 59805), or combinations thereof. Vat dyes are preferredfor cellu losic materials that will be subjected to hard wear, andconsiderable washing.

Other dyes that may be employed are the direct cotton colors, such asDirect Yellow 4 (Color Index No. 24890), Direct Yellow 6 (Color IndexNo. 40001), Direct Orange 1 (Color Index No. 22375), Direct Violet 9(Color Index No. 27885), Direct Blue 67 (Color Index No. 27925 orcombinations thereof, and the like. While we have given the above dyesby way of illustration, We are not limiting our invention to theseparticular dyes. The color index numbers of the dyes, shown inparentheses, were taken from Color Index, 2nd Edition, 1956.

It is an advantage of this invention that when a dyed fabric has beenimpregnated with the crosslinking agent, a catalyst deactivator applied,and the treated cellulosic material subsequently cured, subsequentdyeing with a dye having a different shade enables the opeartor todetermine the depth to which the deactivating chemical is pentrating.into the fabric as the crosslinked or modified cellulosic material willbe dyed a difl erent shade than the unmodified surface.

'It is a further advantage of our invention that the shade and depth ofcolor of the dyed, wash-wear, abrasion-resistant fabrics of thisinvention are not impaired by the presence of a nitrogenous crosslinkingagent. It is well known that many wash-wear finishes based uponnitrogenous crosslinking agents cause accelerated fading of dyes whenexposed to ultraviolet or visible light waves. Just why this occurs isnot presently understood. However, the shades of the dyed products ofour invention do not exhibit accelerated fading because the surface ofthe dyed fabric is free from crosslinked cellulose.

Some finishes on white goods based upon crosslinking agents applied byconventional processes become yellow or discolored when heated, as byironing, or drying in a home dryer, or when bleached with hypochlorite.This discoloration limits the usefulness of such crosslinking agents tomaterials dyed a dark shade. It is a further advantage of our inventionthat such finishes can be used in the production of undyed productswithout exhibiting this discoloration because the surface of the fabricis free of the finish that produces the discoloration.

It is a still further advantage of the product of our invention that theoriginal tensile strengthof the preferentially-crosslinked fabric ishigher than when the crosslinking material is distributed throughout thefabric. Most important, the wrinkle resistance of the fabric is just asgood as though the crosslinking material was distributed throughout thefabric structure. This was unexpected.

In another embodiment of this invention, polyfunctional reagents capableof crosslinking cellulosic molecules and which are catalyzed by Lewisbases may be used. After impregnating the cellulosic materials with anaqueous solution comprising the polyfunctional agent and apolymerization catalyst for said polyfunctional reagent, these catalystsmay then be deactivated by Lewis acids in selected portions of thefabric. These selected portions may be on one or both sides (surfaces)of the fabric or as designs. However, it is a critical feature of thisembodiment that the catalyst-deactivator penetrates less than half thethickness of the cellulosic material so that the molcules of cellulosein the interior are crosslinked after a heat-cure.

Polyfunctional reagents which may be used include dimethylol urea,*bis(hydroxyethyl) sulfone, vinyl cyclohexane diepoxide, epichlorhydrin,tris-(sulfatoethyl), and sulfonium chloride, and the like.

Lewis bases which may be used to catalyze these polyfunction-al agentsare alkali carbonate, alkalies, and alkali bicarbonates.

Lewis acids suitable for deactivating the Lewis-base catalysts includesolutions of acetic acid, hydrochloric acid, oxalic acid, zinc nitrate,magnesium chloride, and the like. .The deactivator may be applied by anyof the methods described above.

The following examples are set forth by way of illustartion only, and itwill be understood that the invention is not to be construed as limitedin spirit or in scope by the details therein. Temperatures are given indegrees Fahrenheit unless otherwise noted. All parts and percentages areby weight. When the weight is based on the solution it will be noted(OIWS). )When the weight is based on the weight of the fiber it will benoted (OWF). Fabrics dyed with va dyes are applied by conventionalvat-dyeing procedures. Dyeings with direct dyes are also applied byconventional direct-dyeing procedures. Test results are according tostandard test methods, as

designated by the American Association of Textile Chemists and Colorists(AATCC) or the American Society for Testing Materials (ASTM).

6 Example 1 A sample of 48", 1.21 yd., 76 x 132, midwale corduroy isdesized, scoured, and dyed with a brown vat dye using standardvat-dyeing procedures. The fabric is then dried at a width of 45". Thedry, desized, scoured, and dyed fabric is then passed into and through asolution containing 12% of the dimethylol derivative ofN,N-dimethylol-4,5-dihydroxy ethylene urea, 2.2% magnesium chloridehexahydrate, 2% polyethylene softener, balance water. The thoroughlyimpregnated fabric is squeezed o a wet takeup of 65 weight percent. Thefabric is then dried at 250 F. for about one minute to obtain a moisturecontent of about 10% by weight of the fabric. The dry fabric is thenknife-blade coated with a solution of 0.8% hydroxyethyl cellulose and0.8% sodium bicarbonate. The solution has a viscosity of about 25 poisesat 25 C. and the coating speed and knife-blade pressure are set toobtain a wet takeup of about 40% based on the weight of the fabric. Thiscoating treatment provides sufficient sodium bicarbonate to neutralizeapproximately 6 of the magnesium chloride hexahydrate catalyst presentin the fabric. The fabric is then dried for about one minute at 250 F.After drying, the fabric is hot pressed to form pleats and creases. Thefabric is then heat-cured at 320 F. for about 10 minutes. After curing,the fabric is washed in Water containing about 0.1% scouring assistant,then dried, and tested.

The results follow:

(1) The surface of the fabric coated with the catalystinactivating agentwhen dyed with Direct Blue 67 is similar in shade to untreated cottonwhen dyed With the same dye.

(2) The surface and interior portion of the fabric not treated with thecatalyst-inactivating agent resisted dyeing with the Direct Blue 67.

(3) The portions of fibers shaved from the surface of the fabric thatreceived a catalyst-inactivation treatment are soluble in cuprammoniumhydroxide and cupriethylene diamine hydroxide (cuene) as are untreatedcotton fibers. This test indicates that crosslinking has not occurredbetween the cotton cellulose molecules of the surface fibers.

(4) The portion of fibers shaved from the surface of the fabric (dyedbrown) which did not receive a catalystinactivation treatment areinsoluble in all normal cellulose dissolving agents, such ascupriethylene diamine hydroxide (cuene). This test indicates that thecotton cellulose molecules are covalently crosslinked. For those fibersthat pass from one surface to the other, in each case the portion of thefiber is soluble or insoluble depending on whether it has been reachedby the catalystinactivation treatment or has not.

(5) The wrinkle-resistance and smooth-drying properties of the treatedfabric are much improved in comparison to the untreated cotton fabric.According to AATCC test method 88C-1964T, the treated fabrics had awashwear rating of 5 after home laundering and tumble drying. Theuntreated fabrics had a rating of 2 after the same treatment.

(6) The results of flex and flat abrasion test according to ASTM-Dl-61T,Method B, show that the side of the fabric given thecatalyst-inactivation treatment has abrasion proporties similar tountreated cotton and has as much as 10-20 times more resistance toabrasive damage than fabric not given the catalyst-inactivationtreatment, or a fabric that has been given a conventional paddry-c-ureresin treatment.

(7) Creases and pleats pressed into the fabric prior to curing are verysharp and durable through repeated washand tumble-dry cycles. There isno evidence of edge abrasion or fibrilation as is typically experiencedwith the surface of wash-wear fabrics produced by conventional wash-wearprocesses.

When quantities of other Lewis bases, such as alkalimetal hydroxides,calcium hydroxide, triethanolamine,

and the sodium salt of carboxymethyl cellulose equivalent to 0.8 weightpercent (OWS) of sodium bicarbonate are used, generally similar resultsare obtained.

Example 2 A sample of 46", 1.95 yd., 128 x 56, twill is desized,scoured, and dyed an olive drab shade using the required combination ofvat dyes. The fabric is then dried at a width of 43". The dry, desized,scoured, and dyed fabric is padded into, and through, a solutioncontaining 12% dirncthylol ethylene urea, 2% magnesium chloridehexahydrate, 2% polyethylene softener, and the balance water tothoroughly impregnate the cellulosic material. The thoroughlyimpregnated fabric is squeezed to a wet pickup of about 65%. The fabricis then dried at 250 F. for about 45 seconds to obtain a moisturecontent of about by weight of the fabric. The dry fabric is thenknifeblade coated successively on the face and on the back with asolution of 1.0% hydroxyethyl cellulose and 0.8% sodium bicarbonate.This solution has a viscosity of about 45 poises at C., and the coatingspeed and knife-blade pressure were set to obtain a combined (i.e., topand bottom side) wet takeup of about based on the weight of the fabric,or a takeup of approximately 20% on each side. This coating treatmentprovides sufiicient sodium bicarbonate to neutralize approximately /2 ofthe magnesium chloride hexahydrate catalyst in the fabric. This isequivalent to neutralizing approximately of the fabric on each side. Thefabric is then dried for about seconds at 250 F. After drying the fabricis pleated and creased by hot pressing. It is then cured at 320 F. forabout ten minutes. After curing the fabric is washed in an aqueous bathcontaining 0.1% scouring assistant, dried, and tested.

The results follow:

(1) The surfaces of the fabric coated with the catalystinactivaiingagent when dyed With Direct Blue 67 is Similar in shade to untreatedcotton when dyed with the same dye.

(2) The interior portions of the fabric not treated with thecatalyst-inactivating agent resisted dyeing with the Direct Blue 67.

(3) The portions of fibers shaved from either fabric surface thatreceived a catalyst-inactivation treatment are soluble in cuprammoniumhydroxide and cupriethylene diamine hydroxide (cuene) as are untreatedcotton fibers. This test indicates that crosslinking has not occurredbetween the cotton cellulose molecules of the surface fibers.

(4) The portions of fibers removed from the interior of the fabric (dyedolive drab) which did not receive a catalyst-inactivation treatment areinsoluble in all normal cellulose dissolving agents, such ascupriethylene diamine hydroxide (cuene). This test indicates that thecotton cellulose molecules are covalently crosslinked. For those fibersthat pass from one surface to the other, in each case the portion of thefiber is soluble or insoluble depending on whether it has been reachedby the catalystinactivation treatment or has not.

(5) The wrinkle-resistance and smooth-drying properties of the treatedfabric are much improved in comparison to the untreated cotton fabric.According to AATCC test method 88C-1964T, the treated fabrics had awash-wear rating of 5 after home laundering and tumble drying. Theuntreated fabrics had a rating of 2 after the same treatment.

(6) The results of flex and fiat abrasion test according toASTM-D1175-61T, Method B, show that the side of the fabric given thecatalyst-inactivation treatment has abrasion properties similar tountreated cotton and has as much as 10-20 times more resistance toabrasive damage than fabric not given the catalyst-inactivationtreatment, or a fabric that has been given a conventional pad-drycureresin treatment.

(7) Creases and pleats pressed into the fabric prior to u i g are verysharp and durable through repeated washand tumble-dry cycles. There isno evidence of edge abrasion or fibrilation as is typically experiencedwith the surface of wash-wear fabrics produced by conventional wash-wearprocesses.

When quantities of other Lewis bases, such as alkalimetal hydroxides,calcium hydroxide, triethanolamine, and the sodium salt of carboxymethylcellulose equivalent to 0.8 weight percent (OWS) of sodium bicarbonateare used, generally similar results are obtained.

Example 3 A sample of 40", 4 yd., 80 x 80, printcloth is desized,scoured, and dyed with a brown vat dye. The fabric is then dried at awidth of 37". The dry desized, scoured, and dyed fabric is passe into,and through, a solution containing 10% dimethylol ethyl carbamate, 2%magnesium chloride hexahydrate, 2% polyethylene softener, balance water.The thoroughly impregnated fabric is squeezed to a wet takeup of aboutThe fabric is dried for 18 seconds at 250 F. to obtain a moisturecontent of about 10% or about normal regain moisture content. The dryfabric is then passed through a fogging chamber containing 0.4 weightpercent sodium hydroxide in water solution and in a very finely dividedspray. The rate of passage of the fabric through the fogging chamber,dwell time, is set to obtain a wet takeup of about 40%. The sodiumhydroxide concentration is adjusted to neutralize from approximatelyone-fourth to one-half of the catalyst in the fabric. The fabric is thendried for 25 seconds at 250 F. Pleats and creases are hot pressed intothe fabric. The fabric is then cured at 320 F. for eight minutes. Aftercuring, the fabric is washed in an aqueous solution containing 0.1%scouring assistant, dried, and tested.

The results follow:

(1) The surfaces of the fabric treated with the catalystinactivatingagent when dyed with Direct Blue 67 is similar in shade to untreatedcotton when dyed with the same dye.

(2) The interior portions of the fabric not treated with thecatalyst-inactivating agent resisted dyeing with the Direct Blue 67.

(3) The portions of fibers shaved from either fabric surface thatreceived a catalyst-inactivation treatment are soluble in cuprammoniumhydroxide and cupriethylene diamine hydroxide (cuene) as are untreatedcotton fibers. This test indicates that crosslinking has not occurredbetween the cotton cellulose molecules of the surface fibers.

(4) The portions of fibers removed from the interior of the fabric (dyedbrown) which did not receive a catalyst-inactivation treatment areinsoluble in all normal cellulose dissolving agents, such ascupriethylene diamine hydroxide (cuene). This test indicates that thecotton cellulose molecules are covalently crosslinked. For those fibersthat pass from one surface to the other, in each case the portion of thefiber is soluble or insoluble depending on whether it has been reachedby the catalystinactivation treatment or has not.

(5) The wrinkle-resistance and smooth-drying properties of the treatedfabric are much improved in comparison to the untreated cotton fabric.According to AATCC test method 88C-1964T, the treated fabrics had awash- Wear rating of 5 after home laundering and tumble drying. Theuntreated fabrics had a rating of 2 after the same treatment.

(6) The results of flex and flat abrasion tests according toASTM-Dll-61T, Method B, show that the side of the fabric given thecatalyst-inactivation treatment has abrasion properties similar tountreated cotton and has as much as l0-20 times more resistance toabrasive damage than fabric not given the catalyst-inactivationtreatment, or a fabric that has been given a conventional pad-drycureresin treatment.

(7) Creases and pleats pressed into the fabric prior to curing are verysharp and durable through repeated washand tumble-dry cycles, There isno evidence of edge abrasion or fibrilation as is typically experiencedwith the surface of wash-wear fabrics produced -by conventionalwash-wear processes.

When quantities of other Lewis bases, such as alkalimetal hydroxides,calcium hydroxide, triethanolamine, and the sodium salt of carboxymethylcellulose equivalent to 0.8 weight percent (OWS) of sodium bicarbonateare used, generally similar results are obtained.

We claim:

1. A process for producing a wrinkle-resistant, smoothdrying, and highabrasion-resistant woven cellulose fabric, comprising (a) impregnating aWoven cellulose fabric containing cellulose yarns entirely through itscross section with a solution containing a crosslinking, creaseproofingagent for cellulose and a catalyst for activating said crosslinking,creaseproofing agent;

(b) drying the thus-impregnated fabric;

(c) applying a catalyst-deactivator to the dried, impregnated fabric sothat it contacts both entire surfaces of the fabric and that portion ofthe interior of the fabric cross section which is continuous with eachof the surfaces and which extends to less than about /2 of the thicknessof the fabric, to deactivate said catalyst in the areas contacted; and

(d) heating the resulting fabric at an elevated temperature to effectreaction between the crosslinking, creaseproofing agent and that portionof the interior of the fabric in which the catalyst has not beendeactivated.

References Cited UNITED STATES PATENTS 1,741,637 12/1929 Lilienfeld 8116XR 2,093,651 9/1937 Widmer 8116 XR 2,493,381 1/1950 Balassa 8l16.3 XR2,752,269 6/1956 Condo et a1. 8116 XR 3,036,932 5/1962 Masarguppi et al.81'16.3 XR 3,068,836 12/1962 Spencer 8-120 XR 3,096,524 7/1963 Mizell8-1l6.3 XR

OTHER REFERENCES Lynn, J. Edward et al.: Advances in Textile Processing,vol. 1, 1961, pp. 45-48 and 60, Textile Book Publishers, Inc., N.Y.C.,N.Y.

NORMAN G. TORCHIN, Primary Examiner.

J. C. CANNON, Assistant Examiner.

